Mortar board



Sept. 27, 1932. R. A. Rou'r'r 11,879,515

MORTAR BOARD Filed April 27, 1951 Ruhaf HULLTT ATTGRNEYS.

Patented Sept. 27, 1932 ROBERT A. ROUTT, OF HTCHINSON, KANSAS MORTAR BOARD Application led April 27,

The present invention relates to mortar boards and the primary object of the invention is to provide an improvedmortar board embodying heating means for preventing freezing of mortar placed upon the board and thereby permitting proper handling of the mortar in freezing weather.

A further object of the invention is to provide a mortar board of this character wherein the heating means is readily removable when not required for preventing freezing of the mortar.

A further object of the invention is to provide a metal mortar board provided with a novel type of heating means adapted to be removably positioned beneath the topV plate or board proper.

Other objects and advantages of the invention will be apparent during the course of the following detailed description, taken in connection with the accompanying drawing forming a part of this specification and in which drawing Figure 1 is a side elevation of the improved mortar board.

Figure 2 is a bottom plan view thereof.

Figure 3 is an enlarged vertical section on the line 3-3 of Figure 1.

In the drawing, and wherein similar reference characters designate corresponding parts thruout the several views, the mortar board comprises a stand A and heating means B removably associated with the stand A.

The stand A embodies a flat metal top plate f' 5 which may be formed from a suitable gauge of sheet steel and preferably of square shape and having the corners rounded H as shown in Figure 2. Secured as by welding to the under side of the top plate or board proper 5 are four lengths of angle iron 6 providing a reinforcing frame for the plate 5. These angle iron strips 6 are welded to the plate 5 in parallel relation to the edges of the plate and have their `horizontal flanges direct-ed inwardly toward the center of the plate. The angle irons 6 may be spaced a slight distance inwardly from the marginal edges of the top plate. Secured as by welding or any other suitable manner to the corner portions of the reinforcing frame are angle iron supporting 1931. serial No. 533,300.

legs 7 and these supporting legs may be of any preferred shape for disposing the mortar receiving top plate a desired distance above the floor surface or scaffold upon which the device is placed. Connected as by welding f or the like to the lower portion offeach leg 7 are horizontal brace members or rods 8 which may alsobe formed from angle iron and are connected at their inner ends as by welding, to a ring member 9 disposed in vertical alignment beneath the axial center of the top plate 5. Y

The heating means B for warming motar placed upon the top plate 5 embodies a heating cone 10 which may be formed from sheet metal and this cone 1s suspended in an inverted position beneath the top plate 5. The upper larger end of the cone 10 is of a diameter equal to the spacing between the parallel pairs of reinforcing angle irons 6. Secured in any preferred manner to the upper open side of the cone 10 and spaced 90o apart, are supporting straps 12 having portions extending above the top edge of the cone' for engagement with the inner surfaces of the downturned anges or legs of the angle irons 6. The angle irons 6'are each provided midway their ends with an elongated slot 14 adapt-ed to receive the shanks of attaching bolts 15 threaded into screw threaded openings 16 providedin the upper projecting ends of the straps 12. The slots 14 are to permit ready and easy mounting of the heating cone by not requiring the threaded openings 16 to be aligned. with similar circular openings provided in the downturned flanges of the members 6. The heating cone 10 when suspended by the straps 12 has its upper edge spaced slightly below the `reinforcing frame members 6 to permit escape of hot air at the upper side of the cone. The cone 10 forms a heat chamber beneath the top plate 5 and the downturned flanges of the reinforcing members 6 act to prevent too free escape of the hotl air across the under side of the top plate. When the heating cone is in position, its lower smaller end is spaced slightly above the braces 8 with the opening 16 of the cone arranged concentric with the ring member 9.

The ring member 9 forms a socket for reused. The fuel tank 22 may be provided with a suitable eye 23 for detachably suspending the tank from a hook 24 attached to the upper end of one of the legs 7. Thus it will be seen that the cone 10 and burner 2O together' with its fuel supply container 22 may be readily detached from the frame A when the heating means is not required for preventing freezing of the mortar.

The fiat metal top plate 5 aside from maintaining the heat for a considerable length of time, also overcomes the obj eotions to the wooden mortar board such as warping and raising of nails used for fastening the top board to the underlying cleats. rIhe reinforcing rails 6 for the top plate aid in providing a more uniform distribution of heat be neath the top plate by 'trapping a portion of the heat inwardly of the downturned flanges of the rails.

` From the foregoing description it will be apparent that a. novel and improved type of mortar board has been provided embodying a novel arrangement whereby mortar placed upon the board may be maintained in a soft condition against freezing. It will also be apparent that a novel arrangement has been disclosed whereby the heating means may be readily detached from the stand when being used in summer or warm climates.

Changes in detail may be made to the form of invention herein shown and described, without departing from the spirit of the invention or the scope of the following claims.

I claim:

l. In a mortar board of the class described, a stand comprising a meta-l top plate, angle iron rails secured by one flange to the under side of the top plate and providing a squareshaped reinforcing frame, an angle iron supporting leg secured to each corner portion of the reinforcing frame, brace rods connecting diagonally opposite supporting legs, an open ended inverted frusto-conical shaped hot air shield detachably supported at its upper end upon the reinforcing frame in slightly spaced relation at its upper end below the top plate and with its lower open end spaced above the brace rods, a burner removably supported upon said brace rods below the hot air shield, a fuel container detachably secured yto the stand beneath the top plate, and a fuel feed line connecting the fuel container and burner.

2; In a mortar board' of the class described, a stand comprising a metal top plate, angle iron rails secured by one flange to the under side of the top plate and providing a squareshaped reinforcing frame, an angle iron supporting leg secured to each corner portion of the reinforcing frame, brace rods connecting diagonally opposite supporting legs, an inverted frusto-conical shaped shield arranged between the top plate and brace rods, mounting straps attached to the upper portion of the shield, means detachably connecting the mounting straps to the depending flanges of said rails for independently supporting the shield in slightly spaced relation below the top plate, a burner removably supported by the brace rods for directing heat into the lower end of the shield, and fuel supply means for the burner including a fuel container detachably secured to one of said supporting legs.

3. In a mortar board of the class described, a stand comprising a metal top plate, angle iron rails secured by one flange to the under side of the top plate and providing a squaresliaped reinforcing frame, an angle iron supporting leg secured to each corner portion of the reinforcing frame, brace rods connecting diagonally opposite supporting legs and joined by a tubular socket at their point of intersection, an inverted frusto-conical shaped shield pendently and removably supported from said rails axially above said socket, a burner removably fitting in the socket, and fuel supply means for the burner.

4. In a mortar board the combination of a flat top plate, a square-shaped reinforcing frame of angle iron rails secured by one flange to the under side of the top plate, supporting legs for the top plate; brace rods connecting the lower portions of the legs, an upwardly flaring frusto-conical shaped shield pendently hung from said rails with its upper end in slightly spaced relation beneath the top plate, said shield having a diameter at its upper end no greater than the cross dimensions of the reinforcing frame, a burner mounted on the brace rods axially beneath the s iield for directing heat upwardly in the shield, and fuel supply means for the burner.

ROBERT A. ROUTT. 

